[
https://issues.apache.org/jira/browse/HADOOP-18752?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17744735#comment-17744735
]
ASF GitHub Bot commented on HADOOP-18752:
-----------------------------------------
steveloughran opened a new pull request, #5859:
URL: https://github.com/apache/hadoop/pull/5859
This change has all of PR #5689 *except* for changing the default value of
marker retention from keep to delete.
1. leaves the default value of fs.s3a.directory.marker.retention at "delete"
2. no longer prints a message when an S3A FS instances is instantiated with
any option other than delete.
3. Updates the directory marker documentation
Switching to marker retention improves performance on any S3 bucket as there
are no needless marker DELETE requests -leading to a reduction in write IOPS
and and any delays waiting for the DELETE call to finish.
There are *very* significant improvements on versioned buckets, where
tombstone markers slow down LIST operations: the more tombstones there are, the
worse query planning gets.
Having versioning enabled on production stores is the foundation of any data
protection strategy, so this has tangible benefits in production.
Marker deletion is *not* compatible with older hadoop releases; specifically
- Hadoop branch 2 < 2.10.2
- Any release of Hadoop 3.0.x and Hadoop 3.1.x
- Hadoop 3.2.0 and 3.2.1
- Hadoop 3.3.0 Incompatible releases have no problems reading data in stores
where markers are retained, but can get confused when deleting or renaming
directories.
Contributed by Steve Loughran
Change-Id: Ic9a05357a4b1b1ff6dfecf8b0f30e1eeedb2fe75
<!--
Thanks for sending a pull request!
1. If this is your first time, please read our contributor guidelines:
https://cwiki.apache.org/confluence/display/HADOOP/How+To+Contribute
2. Make sure your PR title starts with JIRA issue id, e.g.,
'HADOOP-17799. Your PR title ...'.
-->
### Description of PR
### How was this patch tested?
### For code changes:
- [ ] Does the title or this PR starts with the corresponding JIRA issue id
(e.g. 'HADOOP-17799. Your PR title ...')?
- [ ] Object storage: have the integration tests been executed and the
endpoint declared according to the connector-specific documentation?
- [ ] If adding new dependencies to the code, are these dependencies
licensed in a way that is compatible for inclusion under [ASF
2.0](http://www.apache.org/legal/resolved.html#category-a)?
- [ ] If applicable, have you updated the `LICENSE`, `LICENSE-binary`,
`NOTICE-binary` files?
> Change fs.s3a.directory.marker.retention to "keep"
> --------------------------------------------------
>
> Key: HADOOP-18752
> URL: https://issues.apache.org/jira/browse/HADOOP-18752
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/s3
> Affects Versions: 3.3.5
> Reporter: Steve Loughran
> Assignee: Steve Loughran
> Priority: Major
> Labels: pull-request-available
> Fix For: 3.4.0
>
>
> Change the default value of "fs.s3a.directory.marker.retention" to keep;
> update docs to match.
> maybe include with HADOOP-17802 so we don't blow up with fewer markers being
> created.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: common-issues-h...@hadoop.apache.org
